Prevalence and penetrance of ZFPM2 mutations and deletions causing congenital diaphragmatic hernia.

Zinc finger protein, FOG2 family member 2 (ZFPM2) (previously named FOG2) gene defects result in the highly morbid congenital diaphragmatic hernia (CDH) in humans and animal models. In a cohort of 275 CDH patient exomes, we estimated the prevalence of damaging ZFPM2 mutations to be almost 5%. Genetic analysis of a multigenerational family identified a heritable intragenic ZFPM2 deletion with an estimated penetrance of 37.5%, which has important implications for genetic counseling. Similarly, a low penetrance ZFPM2 frameshift mutation was observed in a second multiplex family. Isolated CDH was the predominant phenotype observed in our ZFPM2 mutation patients. Findings from the patients described herein indicate that ZFPM2 point mutations or deletions are a recurring cause of CDH.

Genome-wide gene expression profiling of SCID mice with T-cell-mediated Colitis.

Inflammatory bowel disease (IBD) is a multifactorial disorder with an unknown aetiology. The aim of this study is to employ a murine model of IBD to identify pathways and genes, which may play a key role in the pathogenesis of IBD and could be important for discovery of new disease markers in human disease. Here, we have investigated severe combined immunodeficient (SCID) mice, which upon adoptive transfer with concanavalin A-activated CD4(+) T cells develop inflammation of the colon with predominance in rectum. Mice with increasing level of inflammation was studied. RNA from rectum of transplanted and non-transplanted SCID mice was investigated by a genome-wide gene expression analysis using the Affymetrix mouse expression array 430A (MOE430A) including 22,626 probe sets. A significant change in gene expression (P = 0.00001) is observed in 152 of the genes between the non-transplanted control mice and colitis mice, and among these genes there is an overrepresentation of genes involved in inflammatory processes. Some of the most significant genes showing higher expression encode S100A proteins and chemokines involved in trafficking of leucocytes in inflammatory areas. Classification by gene clustering based on the genes with the significantly altered gene expression corresponds to two different levels of inflammation as established by the histological scoring of the inflamed rectum. These data demonstrate that this SCID T-cell transfer model is a useful animal model for human IBD and can be used for suggesting candidate genes involved in the pathogenesis and for identifying new molecular markers of chronic inflammation in human IBD.

Identification of T1D susceptibility genes within the MHC region by combining protein interaction networks and SNP genotyping data.

AIM: To develop novel methods for identifying new genes that contribute to the risk of developing type 1 diabetes within the Major Histocompatibility Complex (MHC) region on chromosome 6, independently of the known linkage disequilibrium (LD) between human leucocyte antigen (HLA)-DRB1, -DQA1, -DQB1 genes. METHODS: We have developed a novel method that combines single nucleotide polymorphism (SNP) genotyping data with protein-protein interaction (ppi) networks to identify disease-associated network modules enriched for proteins encoded from the MHC region. Approximately 2500 SNPs located in the 4 Mb MHC region were analysed in 1000 affected offspring trios generated by the Type 1 Diabetes Genetics Consortium (T1DGC). The most associated SNP in each gene was chosen and genes were mapped to ppi networks for identification of interaction partners. The association testing and resulting interacting protein modules were statistically evaluated using permutation. RESULTS: A total of 151 genes could be mapped to nodes within the protein interaction network and their interaction partners were identified. Five protein interaction modules reached statistical significance using this approach. The identified proteins are well known in the pathogenesis of T1D, but the modules also contain additional candidates that have been implicated in beta-cell development and diabetic complications. CONCLUSIONS: The extensive LD within the MHC region makes it important to develop new methods for analysing genotyping data for identification of additional risk genes for T1D. Combining genetic data with knowledge about functional pathways provides new insight into mechanisms underlying T1D.

The effects of unilateral knee immobilization on lower extremity gait mechanics.

The purpose of this study was to identify the effects of knee immobilization on uninvolved lower extremity joints during gait. Video and force platform data were collected for seven subjects walking normally (N) and with the knee fixed at three flexion angles: 0 degrees (B00), 10 degrees (B10), and 20 degrees (B20). A bilateral, sagittal plane link-segment model was used to determine lower limb kinematic and kinetic measures. Mean data from three normal and five braced gait trials were compared using one-way repeated measures ANOVA (P < 0.05). Significant increases in involved limb (IL) ankle generation work (J.kg-1) during propulsion were evident: (N = 0.249, B00 = 0.295, B10 = 0.293, B20 = 0.308). There were significant increases in peak IL hip power (W.kg-1) in early stance (N = 0.638, B00 = 1.056, B10 = 1.018, B20 = 1.097) and in IL hip absorption work (J.kg-1) during late stance (N = 0.049, B00 = 0.080, B10 = 0.082, B20 = 0.079). The hip of the uninvolved limb (UL) displayed significant increases in generation work (J.kg-1) in early stance (N = 0.089, B00 = 0.183, B10 = 0.149, B20 = 0.179). Normal kinematic and kinetic patterns of other joints were changed with knee immobilization. The major effects were increases in the magnitude of IL peak hip and ankle joint kinetic measures. Fixing the knee in 10 degrees of flexion resulted in the fewest significant changes in normal gait mechanics.